An image reading device is provided in a variety of electronic appliances, such as digital scanners, copiers, facsimiles, and the like, as well as devices combining some of the functions thereof, and serves to read image information recorded on a document.
Generally, an image reading device may include an illuminator to irradiate light to a document, an image sensor to sense the light reflected from the document, and an optical system to guide the reflected light from the document to the image sensor. The illuminator may include a light source to generate light and a light guide to guide the light generated from the light source toward the document.
An illuminator with a light guide is also often used as a charge eliminator to eliminate or reduce electric potential remaining on a surface of a photosensitive body provided in an electro-photographic image forming apparatus, such as, for example, a laser printer and a digital copier.
To assure good performance of the image reading device and/or the charge eliminator, an illuminator desirably irradiates light uniformly or near uniformly in the main scanning direction and/or in the sub scanning direction.